﻿/*----------------------------------------------------------------------------------------
*
*  Copyright 2019, Gao Hai Hui, <fromzeropoint@126.com>.  All rights reserved.
*  https://gitee.com/helloworldghh/xoskit.git
*  Use of this source code is governed by a MIT license
*  that can be found in the License file.
*
----------------------------------------------------------------------------------------*/
#include "../import/head.h"
#include "../global/head.h"
#include <iostream> 
#include <cstdlib> 
#include <cstring> 
#include <memory.h> 
#include "des.h"

/////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
// 实现

namespace xos_common
{
    /////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
    // 实现

    //typedef bool (*PSubKey)[16][48]; 

    // 初始置换 
    const static char Table_IP[64] = 
    { 
        58, 50, 42, 34, 26, 18, 10, 2, 60, 52, 44, 36, 28, 20, 12, 4, 
        62, 54, 46, 38, 30, 22, 14, 6, 64, 56, 48, 40, 32, 24, 16, 8, 
        57, 49, 41, 33, 25, 17,  9, 1, 59, 51, 43, 35, 27, 19, 11, 3, 
        61, 53, 45, 37, 29, 21, 13, 5, 63, 55, 47, 39, 31, 23, 15, 7 
    }; 

    // 末置换 
    const static char Table_InverseIP[64] = 
    { 
        40, 8, 48, 16, 56, 24, 64, 32, 39, 7, 47, 15, 55, 23, 63, 31, 
        38, 6, 46, 14, 54, 22, 62, 30, 37, 5, 45, 13, 53, 21, 61, 29, 
        36, 4, 44, 12, 52, 20, 60, 28, 35, 3, 43, 11, 51, 19, 59, 27, 
        34, 2, 42, 10, 50, 18, 58, 26, 33, 1, 41,  9, 49, 17, 57, 25 
    }; 

    // 扩展置换 
    static const char Table_E[48] = 
    { 
        32,  1,  2,  3,  4,  5,  4,  5,  6,  7,  8,  9, 
        8,  9, 10, 11, 12, 13, 12, 13, 14, 15, 16, 17, 
        16, 17, 18, 19, 20, 21, 20, 21, 22, 23, 24, 25, 
        24, 25, 26, 27, 28, 29, 28, 29, 30, 31, 32,  1 
    }; 

    // 密钥初始置换 
    const static char Table_PC1[56] = { 
        57, 49, 41, 33, 25, 17,  9,  1, 58, 50, 42, 34, 26, 18, 
        10,  2, 59, 51, 43, 35, 27, 19, 11,  3, 60, 52, 44, 36, 
        63, 55, 47, 39, 31, 23, 15,  7, 62, 54, 46, 38, 30, 22, 
        14,  6, 61, 53, 45, 37, 29, 21, 13,  5, 28, 20, 12,  4 
    }; 

    // 左移运算 
    const static char Table_Moveleft[16] = 
    { 
        1,1,2,2,2,2,2,2,1,2,2,2,2,2,2,1 
    }; 

    // 密钥压缩置换 
    const static char Table_PC2[48] = 
    { 
        14, 17, 11, 24,  1,  5,  3, 28, 15,  6, 21, 10, 
        23, 19, 12,  4, 26,  8, 16,  7, 27, 20, 13,  2, 
        41, 52, 31, 37, 47, 55, 30, 40, 51, 45, 33, 48, 
        44, 49, 39, 56, 34, 53, 46, 42, 50, 36, 29, 32 
    }; 

    // S盒 
    const static char Box_S[8][4][16] = 
    { 
        // S1 
        {
            { 14, 4, 13, 1,  2, 15, 11,  8,  3, 10,  6, 12,  5,  9,  0,  7      },
            { 0, 15,  7,  4, 14,  2, 13,  1, 10,  6, 12, 11,  9,  5,  3,  8     },
            { 4,  1, 14,  8, 13,  6,  2, 11, 15, 12,  9,  7,  3, 10,  5,  0     },
            { 15, 12,  8,  2,  4,  9,  1,  7,  5, 11,  3, 14, 10,  0,  6, 13    }
        },

        // S2 
        {
            { 15,  1,  8, 14,  6, 11,  3,  4,  9,  7,  2, 13, 12,  0,  5, 10    }, 
            {  3, 13,  4,  7, 15,  2,  8, 14, 12,  0,  1, 10,  6,  9, 11,  5    }, 
            {  0, 14,  7, 11, 10,  4, 13,  1,  5,  8, 12,  6,  9,  3,  2, 15    }, 
            { 13,  8, 10,  1,  3, 15,  4,  2, 11,  6,  7, 12,  0,  5, 14,  9    }
        },

        // S3 
        {
            { 10,  0,  9, 14,  6,  3, 15,  5,  1, 13, 12,  7, 11,  4,  2,  8}, 
            { 13,  7,  0,  9,  3,  4,  6, 10,  2,  8,  5, 14, 12, 11, 15,  1}, 
            { 13,  6,  4,  9,  8, 15,  3,  0, 11,  1,  2, 12,  5, 10, 14,  7}, 
            { 1, 10, 13,  0,  6,  9,  8,  7,  4, 15, 14,  3, 11,  5,  2, 12}
        }, 

        // S4 
        {
            { 7, 13, 14,  3,  0,  6,  9, 10,  1,  2,  8,  5, 11, 12,  4, 15     }, 
            { 13,  8, 11,  5,  6, 15,  0,  3,  4,  7,  2, 12,  1, 10, 14,  9    }, 
            { 10,  6,  9,  0, 12, 11,  7, 13, 15,  1,  3, 14,  5,  2,  8,  4    }, 
            { 3, 15,  0,  6, 10,  1, 13,  8,  9,  4,  5, 11, 12,  7,  2, 14     }
        },

        // S5 
        {
            {2, 12,  4,  1,  7, 10, 11,  6,  8,  5,  3, 15, 13,  0, 14,  9}, 
            {14, 11,  2, 12,  4,  7, 13,  1,  5,  0, 15, 10,  3,  9,  8,  6}, 
            {4,  2,  1, 11, 10, 13,  7,  8, 15,  9, 12,  5,  6,  3,  0, 14}, 
            {11,  8, 12,  7,  1, 14,  2, 13,  6, 15,  0,  9, 10,  4,  5,  3}
        }, 

        // S6
        {
            {12,  1, 10, 15,  9,  2,  6,  8,  0, 13,  3,  4, 14,  7,  5, 11}, 
            {10, 15,  4,  2,  7, 12,  9,  5,  6,  1, 13, 14,  0, 11,  3,  8}, 
            {9, 14, 15,  5,  2,  8, 12,  3,  7,  0,  4, 10,  1, 13, 11,  6}, 
            {4,  3,  2, 12,  9,  5, 15, 10, 11, 14,  1,  7,  6,  0,  8, 13}
        }, 

        // S7
        {
            {4, 11,  2, 14, 15,  0,  8, 13,  3, 12,  9,  7,  5, 10,  6,  1}, 
            {13,  0, 11,  7,  4,  9,  1, 10, 14,  3,  5, 12,  2, 15,  8,  6}, 
            {1,  4, 11, 13, 12,  3,  7, 14, 10, 15,  6,  8,  0,  5,  9,  2}, 
            {6, 11, 13,  8,  1,  4, 10,  7,  9,  5,  0, 15, 14,  2,  3, 12}
        },

        // S8 
        {
            {13,  2,  8,  4,  6, 15, 11,  1, 10,  9,  3, 14,  5,  0, 12,  7}, 
            {1, 15, 13,  8, 10,  3,  7,  4, 12,  5,  6, 11,  0, 14,  9,  2}, 
            {7, 11,  4,  1,  9, 12, 14,  2,  0,  6, 10, 13, 15,  3,  5,  8}, 
            {2,  1, 14,  7,  4, 10,  8, 13, 15, 12,  9,  0,  3,  5,  6, 11 }
        }
    }; 

    // P盒置换 
    const static char Table_P[32] = 
    { 
        16, 7, 20, 21, 29, 12, 28, 17, 1,  15, 23, 26, 5,  18, 31, 10, 
        2,  8, 24, 14, 32, 27, 3,  9,  19, 13, 30, 6,  22, 11, 4,  25 
    }; 

    //static bool SubKey[2][16][48];//两个密钥的16轮子密钥 
    //static char Tmp[256], deskey[16]; 

    /////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
    // 实现

    des::des()
    {
        memset( SubKey, 0, sizeof( SubKey ) );
        memset( Tmp, 0, sizeof( Tmp ) );
        memset( deskey, 0, sizeof( deskey ) );
        memset( m_bM, 0, sizeof( m_bM ) );
    }

    des::~des()
    {
    }

    /////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
    // 实现

    //通用置换函数 
    void des::Transform(bool *Out, bool *In, const char *Table, int len) 
    { 
        for(int i = 0; i < len; ++ i) 
            Tmp[i] = In[ Table[i] - 1 ]; 
        memcpy(Out, Tmp, len); 
    } 

    //异或运算 
    void des::Xor(bool *InA, const bool *InB, int len) 
    { 
        for(int i = 0; i < len; ++ i) 
            InA[i] ^= InB[i]; 
    } 

    //循环左移 
    void des::MoveLeft(bool *In, int len, int loop) 
    { 
        memcpy(Tmp, In, loop); 
        memcpy(In, In + loop, len - loop); 
        memcpy(In + len - loop, Tmp, loop); 
    } 

    //字节转换成位 
    void des::Byte2Bit(bool *Out, const char *In, int bits) 
    { 
        for(int i = 0; i < bits; ++ i) 
            Out[i] = (In[i >> 3] >> (i & 7)) & 1; 
    } 

    //位转换字节 
    void des::Bit2Byte(char *Out, const bool *In, int bits) 
    { 
        memset(Out, 0, bits >> 3); 
        for(int i = 0; i < bits; ++ i) 
            Out[i >> 3] |= In[i] << (i & 7); 
    } 

    //S 盒置换 
    void des::funS(bool Out[32], const bool In[48]) 
    { 
        for(int i = 0, j, k; i < 8; ++ i, In += 6, Out += 4) 
        { 
            j = (In[0] << 1) + In[5]; 
            k = (In[1] << 3) + (In[2] << 2) + (In[3] << 1) + In[4]; 
            Byte2Bit(Out, &Box_S[i][j][k], 4); 
        } 
    } 

    //F 函数 
    void des::funF(bool In[32], const bool Ki[48]) 
    { 
        static bool MR[48]; 
        Transform(MR, In, Table_E, 48); 
        Xor(MR, Ki, 48); 
        funS(In, MR); 
        Transform(In, In, Table_P, 32); 
    } 

    //生成子密钥 
    void des::MakeSubKey(PSubKey pSubKey, const char Key[8]) 
    { 
        static bool K[64], *KL = &K[0], *KR = &K[28]; 
        Byte2Bit(K, Key, 64); 
        Transform(K, K, Table_PC1, 56); 
        for(int i = 0; i < 16; ++ i) 
        { 
            MoveLeft(KL, 28, Table_Moveleft[i]); 
            MoveLeft(KR, 28, Table_Moveleft[i]); 
            Transform((*pSubKey)[i], K, Table_PC2, 48); 
        } 
    } 

    //生成密钥 
    void des::MakeKey(const char* Key, int len) 
    { 
        memset(deskey, 0, 16); 
        memcpy(deskey, Key, len > 16 ? 16 : len); 
        MakeSubKey(&SubKey[1], &deskey[8]); 
    } 

    //一重DES加/解密 
    void des::DES(char Out[8], const char In[8], const PSubKey pSubKey, bool bEncode ) 
    { 
        bool tmp[32] = { 0 }, *Li = &m_bM[0], *Ri = &m_bM[32]; 

        Byte2Bit(m_bM, In, 64); 
        Transform(m_bM, m_bM, Table_IP, 64); 

        if( bEncode )
        { 
            //加密 
            for(int i = 0; i < 16; ++ i) 
            { 
                memcpy(tmp, Ri, 32); 
                funF(Ri, (*pSubKey)[i]); 
                Xor(Ri, Li, 32); 
                memcpy(Li, tmp, 32); 
            } 
        } 
        else //解密 
        { 
            for(int i = 15; i >= 0; -- i) 
            { 
                memcpy(tmp, Li, 32); 
                funF(Li, (*pSubKey)[i]); 
                Xor(Li, Ri, 32); 
                memcpy(Ri, tmp, 32); 
            } 
        }

        Transform(m_bM, m_bM, Table_InverseIP, 64); 
        Bit2Byte(Out, m_bM, 64); 
    } 

    int des::DoDES( char * Out, const char * In, long datalen, const char * Key, int keylen, bool bEncode )
    { 
        int nRet = 0;

        if( 0 == nRet )
        {
            if( !( Out && In && Key && (datalen=(datalen+7)&0xfffffff8) ) ) 
            {
                nRet = 1;
            }
        }

        if( 0 == nRet )
        {
            MakeKey(Key, keylen); 

            // 3次DES 加密:加(key0)-解(key1)-加(key0) 解密:解(key0)-加(key1)-解(key0) 
            for(long i = 0, j = datalen >> 3; i < j; ++ i, Out += 8, In += 8) 
            { 
                DES(Out, In,  &SubKey[0], bEncode ); 
                DES(Out, Out, &SubKey[1], !bEncode ); 
                DES(Out, Out, &SubKey[0], bEncode ); 
            }
        }

        return nRet;
    } 
} // xos_common
